Traumatic Brain Injury Lecture PDF

Lecture 2 Neuropathology of TBI: Biomechanics & Pathophysiology 1 Types of Traumatic Brain Injury Acquired Brain Injury Traumatic brain injury (TBI) Other types of acquired brain injury e.g. Stroke B...

Lecture 2 Neuropathology of TBI: Biomechanics & Pathophysiology 1 Types of Traumatic Brain Injury Acquired Brain Injury Traumatic brain injury (TBI) Other types of acquired brain injury e.g. Stroke Brain tumors Encephalitis Johnson & Jacobson (2017), Ch. 7 Pappathanasiou & Coppens (2017), Ch. 20 2 Types of Traumatic Brain Injury Closed Head Injury Open Head Injury (OHI) (non-penetrating TBI) (penetrating TBI) 3 Types of Traumatic Brain Injury Traumatic Brain Injury Closed Open Head Injury Head Injury (CHI) (OHI) Bullet Car Accident Moving Object Falling Object 4 Types of Traumatic Brain Injury Biomechanics & Pathophysiology 5 Types of Traumatic Brain Injury Open Head Injury (OHI) (penetrating TBI) ✓ Penetration of the skull and meningeal layers of the brain ✓ Focal Damage: Disruption in the neuronal networks along the path of the penetrating object 6 Types of Traumatic Brain Injury Focal Damage Cognitive & communicative deficits specific to the damaged brain region 7  Types of Traumatic Brain Injury Closed Head Injury (CHI) Closed Head Injury (CHI) Car accident Moving Object 8 Types of Traumatic Brain Injury Closed Head Injury (CHI) (nonpenetrating TBI) Most frequent cause of TBI Biomechanics: Key Processes Linear acceleration-deceleration forces Rotational forces Extent of Damage: Primary and secondary damage 9 Types of Traumatic Brain Injury Closed Head Injury (CHI) Primary Damage: Focal and Diffuse Lesions Focal Lesions Due to linear acceleration-deceleration forces Coup: Impact on site of contact Contrecoup: Impact on opposite side of main contact Johnson & Jacobson (2017), Ch. 7 Pappathanasiou & Coppens (2017), Ch. 20 Mesfin FB, Gupta N, Hays Shapshak A, et al. Diffuse Axonal Injury. (2022). Treasure Island (FL): StatPearls Publishing Diffuse Axonal Injury - StatPearls - NCBI Bookshelf (nih.gov) 10 Types of Traumatic Brain Injury Frontal and temporal lobes often compromised from acceleration- deceleration forces What language and cognitive functions are impaired? 11  Types of Traumatic Brain Injury Diffuse/Multifocal Lesions Due to rotational forces Diffuse axonal injury (DAI) Key factor in disrupted neuronal communication Mild DAI: Headache Severe DAI: Loss of consciousness Vegetative state 12 Types of Traumatic Brain Injury Secondary damage Hemorrhage Cerebral edema Intracranial pressure Hypoxia/Ischemia Seizures 13 Types of Traumatic Brain Injury Secondary damage Hemorrhage Cerebral edema Intracranial pressure Hypoxia/Ischemia Seizures 14 Types of Traumatic Brain Injury Combat-related Blast Injury Exposure to a blast may result in injuries from ✓ Impact from blast wave ✓ Impact from debris on skull ✓ Body thrown against a surface by the blast ✓ Inhalation of toxic substances from blast 15 Types of Traumatic Brain Injury Chronic traumatic encephalopathy (CTE) Progressive neuropathology from repetitive blows (concussions) to the head Neuronal degeneration Sustained exposure to repetitive head impacts: Cognitive deficits: memory, executive functions. Neurobehavioral dysregulation: Impulsivity, explosivity Diagnosed by examining brain tissue after death 16 Key Concepts Neuropathology of TBI Types of TBI Biomechanics & Pathophysiology 17  What does Biomechanics of Injury mean in TBI? How are the biomechanics of injury different in OHI and CHI? What is the difference between focal and diffuse damage? Review Questions Why is the extent of DAI a crucial factor in TBI? What is the difference between primary and secondary damage? What are other forms of TBI? 18